School of Life & Health Sciences, Marine Science & Engineering, Hainan University, Hainan, China.
Department of Fisheries & Aquatic Sciences, University of Eldoret, Eldoret, Kenya.
Environ Sci Pollut Res Int. 2024 Oct;31(47):58054-58068. doi: 10.1007/s11356-024-34963-7. Epub 2024 Sep 21.
The urban rivers, including Changwang, Meishe, and Wuyuan in Haikou City, Hainan Island, are vital water sources for agricultural production and support industrial and domestic activities. Despite the rivers experiencing anthropogenic impacts, limited studies have assessed their water quality. Accordingly, this study assessed the phytoplankton community structure, utilized the river phytoplankton assemblage index (Q index) to evaluate the ecological status, and compared its performance with the comprehensive trophic level index (TLI). Sample collection and microscopy analysis was conducted seasonally in 2019. Two hundred ninety-eight phytoplankton species belonging to 8 phyla were identified, predominated by Chlorophyta, Bacillariophyta, and Cyanophyta. The phytoplankton biomass ranged from 0.04 to 34.98 mg L, with averages of 3.06 ± 0.71, 5.16 ± 1.92, and 2.70 ± 0.76 mg L in Changwang, Meishe, and Wuyuan, respectively. The phytoplankton biomass varied seasonally, recording the highest and lowest values in summer and autumn, respectively. The phytoplankton species were classified into 26 functional groups, which exhibited spatial and seasonal differences in their biomass and composition. The redundancy analysis (RDA) revealed that NH-N, TP, COD, Chl-a, salinity, and temperature were the main environmental factors influencing phytoplankton functional groups. The average Q index values in Changwang, Meishe, and Wuyuan were 3.39 ± 0.61, 3.44 ± 0.51, and 3.22 ± 0.67, and all the rivers were rated "good" in status. Seasonally, the Q index and TLI revealed that the rivers' ecological condition was better in autumn and winter compared to spring and summer. Generally, the Q index performed better, indicating that parameters such as NH-N, COD, TP, and Chl-a decreased with improving ecological conditions from "poor" to "excellent" status. In addition, the Q index exhibited a significant negative relationship with TLI, suggesting that low Q index values may indicate increased eutrophication or deteriorated water quality. Thus, the ecological condition of the urban rivers could be adequately assessed using the Q index to guide their water quality monitoring and management.
海口市的昌旺河、美舍河和五源河等城市河流是农业生产的重要水源，也是工业和生活活动的支撑。尽管这些河流受到人为影响，但对其水质的评估研究有限。因此，本研究评估了浮游植物群落结构，利用河流水生生物综合指数（Q 指数）来评价生态状况，并将其与综合营养状态指数（TLI）进行了比较。于 2019 年进行了季节性采样和显微镜分析。共鉴定出 8 个门 298 种浮游植物，其中以绿藻、硅藻和蓝藻为主。浮游植物生物量范围为 0.04 至 34.98 mg/L，昌旺河、美舍河和五源河的平均值分别为 3.06 ± 0.71、5.16 ± 1.92 和 2.70 ± 0.76 mg/L。浮游植物生物量呈季节性变化，夏季和秋季分别达到最高和最低值。浮游植物物种分为 26 个功能群，它们的生物量和组成在空间和季节上存在差异。冗余分析（RDA）表明，NH-N、TP、COD、Chl-a、盐度和温度是影响浮游植物功能群的主要环境因素。昌旺河、美舍河和五源河的平均 Q 指数值分别为 3.39 ± 0.61、3.44 ± 0.51 和 3.22 ± 0.67，所有河流的状态均被评为“良好”。季节性方面，Q 指数和 TLI 表明，与春夏季相比，秋冬季河流的生态条件更好。一般来说，Q 指数表现更好，表明随着生态条件从“差”到“优”的改善，NH-N、COD、TP 和 Chl-a 等参数减少。此外，Q 指数与 TLI 呈显著负相关，表明 Q 指数值较低可能表明富营养化程度增加或水质恶化。因此，可利用 Q 指数充分评估城市河流的生态状况，以指导其水质监测和管理。
